Currently, there are few effective options for the treatment of many common cancer types. The course of treatment for a given individual depends on the diagnosis, the stage to which the disease has developed, and factors such as age, sex, and general health of the patient. The most conventional options of cancer treatment are surgery, radiation therapy, and chemotherapy. Surgery plays a central role in the diagnosis and treatment of cancer. Typically, a surgical approach is required for biopsy and the removal of cancerous growth. However, if the cancer has metastasized and is widespread, surgery is unlikely to result in a cure, and an alternate approach must be taken. Side effects of surgery include diminished structural or organ function and increased risk of infection, bleeding, or coagulation related complications. Radiation therapy, chemotherapy, biotherapy and immunotherapy are alternatives to surgical treatment of cancer (Mayer, 1998; Ohara, 1998; Ho et al., 1998). The disadvantage of many of the alternative therapies are the side effects, which can include myelosuppression, skin irritation, difficulty swallowing, dry mouth, nausea, diarrhea, hair loss, weight loss, and loss of energy (Curran, 1998; Brizel, 1998).
Lactoferrin is a single chain metal binding glycoprotein. Many cells types, such as monocytes, macrophages, lymphocytes, and intestinal brush-border cells, are known to have lactoferrin receptors. In addition to lactoferrin being an essential growth factor for both B and T lymphocytes, lactoferrin has a wide array of functions related to host primary defense mechanisms. For example, lactoferrin has been reported to activate natural killer (NK) cells, induce colony stimulating activity, activate polymorphonuclear neutrophils (PMN), regulate granulopoeisis, enhance antibody-dependent cell cytotoxicity, stimulate lymphokine-activated killer (LAK) cell activity, and potentiate macrophage toxicity.
Recently, bovine lactoferrin (bLF) was used as a prophylaxis for tumor formation and/or established tumors. The present invention is the first to use lactoferrin as a treatment, not a prophylaxis, for established tumors.